A popular feature in film-based cameras is a time-date stamp feature. By choosing to use the time-date stamp feature, camera users easily track when a picture was taken by recording the time and date directly on the picture's image. Some cameras offer variations for the time-date feature that allow users to select a stamp format appropriate for different regions of the world. Usually, a small integrated circuit clock chip in the camera back is included and contains LED's (light emitting diodes), which are lit to directly print on the film when the image is captured.
Other types of stamps are often desirable for different picture-taking situations. For example, professional photographers typically identity their pictures by printing their name or studio logo onto their pictures. In some cases, text indicating that the print is just a proof is used to make the proofs undesirable as final prints but still able to provide an image for making a selection and placing an order. Of course, special equipment is normally required to produce the overprinting on print paper.
With the advancement of cameras from film-base to digital-base, such features remain highly desirable. In general, modern digital cameras for taking pictures of scenes and the like typically include an imaging device which is controlled by a computer running a single threaded process. When an image is captured, the imaging device is exposed to light and generates raw image data representing the image. The raw image data is typically stored in a single image buffer where it is then processed and compressed by the processor. Many types of compression schemes are used to compress the image data, with the joint photographic expert group (JPEG) standard being the most popular. After the processor processes and compresses the raw image data into JPEG image files, the processor stores the JPEG image files into an internal memory or on an external memory card.
Some digital cameras are also equipped with a liquid-crystal display (LCD) or other type of display screen on the back of the camera. Through the use of the LCD, the processor can cause the digital camera to operate in one of two modes, record and play, although some cameras only have a record mode. In record mode, the LCD is used as a viewfinder in which the user may view an object or scene before taking a picture. In play mode, the LCD is used a playback screen for allowing the user to review previously captured images either individually or in arrays of four, nine, or sixteen images.
The ability to form, place, and apply multiple types of stamps is limited in typical digital cameras. For example, to apply a stamp of a text or a logo into a digital image, typically digital cameras require a picture of the text or logo to be taken. The image captured can then be sized and positioned to fit into constrained box positions across the top, middle, or bottom of another captured image. The need to have images captured for any text or graphical element for use as a stamp severely restricts the ability to freely add stamps to digital images. Further, the constrained areas for placement further limits the usefulness of "stamping" through these techniques.
Further, the use of even a time-date stamp in digital images has limitations. Applying a time-date stamp in a digital camera through the use of creation in software and application during image processing is fairly straightforward, however, difficulties arise when the orientation of an image changes. In digital cameras employing an orientation sensor, the image is automatically rotated during image processing, so that the proper orientation is shown when displayed on the LCD. Unfortunately, a problem arises in determining how the application of the time-date stamp adjusts to the orientation of the image.
Therefore, a need exists for a method and system for positioning stamps, including time-date stamps, in digital images that is definable and automatically adjusts to the orientation of the image.